ULTRAVIOLET 250-395nm Gallium Nitride

[[BEGIN SERMON MODE]]
I must emphasize, protect your eyeballs when using any one of these LEDs. You only get one set of eyes - and if you wreck them, you can't just go down to the local seven-eleven and buy a can of them.
Here is one simple way you can do this:

Most sunglasses and some prescription eyeglasses have some degree of UV protection already; to determine if yours do or not, aim the LED at something that clearly fluoresces (such as those neon green & orange stickers that occasionally show up on your mail, day-glow orange price tags, or painted portions of a blacklight poster), positioning the LED so the object in front of it glows (fluoresces) brightly from the ultraviolet light. Then put the glasses between the face of the LED and the target. If the glow stops or dims dramatically, the glasses are stopping the UV and you can use them as eye protection at least for short-term use.
However, if the glow remains or dims only slightly, look for another pair.

In any case, never look directly at the LED without eye protection - not even for a minute.

Symptoms of UV exposure may not appear immediately; they can be delayed by 30 minutes to several hours. They can include a burning or "sand in the eyes" sensation, and a hazy look around light bulbs and other bright objects. Mild cases are self-correcting within 24 to 36 hours; however if despite my warnings you still stared at the LED from close range for more than a few minutes, it might not be a bad idea to see an eye doctor and tell him you've been exposed to UVA radiation.

DISCLAIMER: I shall not be held responsible for any damage or loss of eyesight arising from your use or misuse of the information on this page. Thank you for listening.
[[END SERMON MODE]]




Spectrum of a typical 395nm UV LED using Cree chip.

Nichia NSPU510CS 375nm LED, $TBA
Sent by a website fan on 06-15-09, tested on 06-20-09
This is a fairly new UVA (ultraviolet type A) LED from Nichia; this appears to be their latest entry in the long-running UVA LED wars.

It comes in a standard 5mm round through-hole package with a colorless, water-clear epoxy package.

Power output should be in the range of 5,500W (5.50mW) to 11,900W (11.90mW), depending on this LED's power ranking (bin) - this assumes an If (forward drive current) of 15mA.


Beam photograph on the test target at ~12".
Much of the light you see is fluorescence emission from the target itself.



This is a photograph of the LED's beam on a nonreactive white surface from several inches away.


Spectrographic analysis
Spectrographic analysis of this LED.

Spectrographic analysis
Spectrographic analysis of this LED; spectrometer's range narrowed to 360nm to 400nm.

Additional analysis has revealed that this particular sample has a peak wavelngth of 375.020nm - right on the money as they say.



AdvancedMart, 365nm 5mm UVA LED, $TBA
Received 06-28-07, tested on 06-29-07
This is a 5mm water-clear epoxy bodied LED that emits primarily UVA radiation peaking at 368nm.
An LED that emits UVA isn't exactly new, but this wavelength (365nm) is relatively uncommon.


Photograph of fluorescence in the green part of a Team Edge RC remote control.

Spectrographic analysis
Spectrographic analysis of this LED.
The visible radiation cutoff on this chart is 385nm.



Roithner Lasertechnik, UVTOP255-FW-TO39, 255 nm +/- 5 nm, 20 mA, TO-39, flat window, $441.07
I'm now aware of the existence of this 255nm UV LED (as of 03-10-06), but I have neither tested nor seen one. It has a forward voltage requirement of 6.5 volts to as high as 8.0 volts!!! The If (forward current) is a fairly typical 20mA.

As you can see though, the cost per LED is extremely high (more than $441.00!!!), which is *WHY* they have not been tested at The LED Museum.



Non-Nichia 375nm UVA LED, $7.00
Received and tested on 09-19-05

I purchased one of these LEDs after they were offered on Candlepower Forums, in the Dealer's Corner forum.

This is an LED in a TO-18 metal can, with a glass focusing lens on the end. It emits primarily UVA radiation peaking at 375nm.

This is *NOT* a Nichia LED; the die (light-emitting region) has the wirebonds attached at the flat sides of the chip, not at the corners like Nichia's NSHU590A UV LED.


Photograph of the LED itself.
The LED emits radiation too short in wavelength to be measured with the instruments at my disposal or to furnish a beam photograph.

Spectrographic analysis
Spectrographic analysis of this LED.
Ocean Optics USB2000 Spectrometer on loan from TWO-CUBED.



Nichia NSHU590A 370nm UVA LED, $TBA
Received and tested on 08-29-05
This is an LED in a TO-18 metal can, with a glass focusing lens on the end. It emits primarily UVA radiation peaking at 370nm.



Photograph of the LED itself.


Photograph of the LED's beam on the test target.
The LED emits radiation too short in wavelength to be measured with the instruments at my disposal.



On 08-23-05, I received the following message from a fan of the website:

Just thought I'd mention a cheap and useful UV filter. Rosco makes a UV filter gel for theatrical use (can't remember the part number, it's called Tough UV Filter), and a 20" x 24" sheet of it can be had for around ten dollars from any theatrical retailer or rental house. This, of course, would be enough to make either a bunch of pairs of funny looking protective glasses or a small protective screen for a workbench or something.

It's made to be used in front of discharge lamps in the 2000-5000 watt range, so it's more than adequate for home use. I believe it cuts slightly over 80% of incoming UV, so two layers of it should be sufficient for any LED that's on the market today :) It's very nearly transparent in the visible range, and appears to have a very slight greenish-yellow tinge.

Rosco also makes a somewhat more expensive optically clear IR filter. They make two, one of which is just designed to absorb heat and to melt before your expensive color filters do, but the other actually reflects IR back to the source. The more expensive one, of course, is the one you want.

I'm personally a huge fan of Rosco for all their filters... with a couple white ultrabrights, one of their color correction filters, and a diffusion filter (to get rid of that blue ring-of-ugliness in some white LEDs), I was able to create a light for photographic closeups that actually looked decent on film.








Roithner Lasertechnik, # RLT350-30, $41.38 each
With a peak wavelength of 350nm, this is the shortest wavelength UV LED I've heard of in current production. This is a loaner sample, so I really need to try very hard not to blow it up.
That icon up there means I no longer have this lamp.

This LED comes in a standard 5mm (T1 3/4) round epoxy case, and outputs light at 350nm in the UVA band. To the unaided eye, it produces a dim, violetish-white color; the majority of its output is in the UVA region of the spectrum, invisible to the human eye. The output is stated as 30 W, though I have no way to verify this measurement.

The die (light-emitting region) is artifical sapphire with two bond wires; attached at opposite ends of the die. They aren't attached at the corners, but at the flat ends. This rules out Nichia, Cree, and possibly Uniroyal as the LED's manufacturer.


Photograph showing the LED causing fluorescence in Vaseline glass marbles.
Wavelength is too short for me to take any measurements or beam photographs.



Roithner Lasertechnik, part # RLT365-525
Received and tested on 04-23-04
A fan of the website sent me two of these LEDs, identified as Roithner Lasertechnik's RLT365-525, a 365nm UV LED in a water-clear 5mm epoxy package.

This LED outputs 850W (0.85mW) of ultraviolet radiation at 365nm when driven just under 20mA.
The LED appears to have a dim purplish-white glow to it; most of its output is at 365nm, which is generally considered to be invisible to the human eye. At low currents (just under 2mA), the LED appears to have a weak greenish-white color to it, but still emits UV as it causes UV-reactive substances to fluoresce.


The camera and LED were placed no more than three inches from the target for this photograph, as I could not obtain a picture from the ~12" normally used for this type of photograph. The LED's wavelength was also too short to measure its light output or run it through the ProMetric system.


Picture of a UV-reactive glass marble fluorescing under this LED's light.



Roithner Lasertechnik, part # 385D15
Received on 01-05-04, tested on 01-06-04
I received a bunch of LEDs and a couple of flashlights from Roithner Lasertechnik yesterday (01-05-04), and this LED was among them.

It is a 385nm UV LED in a clear epoxy 5mm case. The die (light-emitting chip) inside is roughly rectangular, with the two bond wires attached at each end, rather than at the corners as is common with other double-bond (InGaN and GaN on artificial sapphire) LEDs.


Beam photograph at ~12"
The purplish magenta color is not how the LED beam really appears.
Test current was approximately 26mA for this photograph.

Wavelength is too short for me to get an intensity or power output reading, or run the LED through the ProMetric. Just by "eyeballing" it though (not recommended with LEDs of this wavelength range!!!), the LED appears to generate 2-4mW of output power.

The LED's UVA light will cause fluorescence in "day-glow" objects, and in glow-in-the-dark (GITD) objects. Use this LED anywhere you need some longwave (UVA) radiation. You should be able to use it for checking antique objects for repairs, looking for cat pee in the rug, checking US paper currency for their fluorescent anti-counterfiet strips (the strips glow when exposed to UVA, and as of January 2004, should be found in all demoninations except $1 bills), and other uses you might need for a UVA light.

Spectrographic analysis
Spectrographic analysis of the 385nm LED.
Ocean Optics USB2000 Spectrometer on loan from TWO-CUBED.



Roithner Lasertechnik, part # 5P4FCA
Received on 01-05-04, tested on 01-06-04
This is a 395nm UV LED in a clear epoxy 5mm case. The die (light-emitting chip) inside is square, with the two bond wires attached at opposite corners. This LED shares most of its characteristics with the one directly above, except that its peak wavelength is 10nm longer and it has a slightly brighter appearance as a result.


Beam photograph at ~12"
Again, the magenta color is not how the LED beam really looks.
Test current was approximately 26mA for this photograph.

For both this LED and the one above, I used the Hosfelt LED tester as a PSU. I used the 30mA jack, knowing it outputs 26mA into a typical GaN LED. Yes, I've measured it, so I know the reading is accurate to +-1mA.

Spectrographic analysis
Spectrographic analysis of this LED.
Ocean Optics USB2000 Spectrometer on loan from TWO-CUBED.



Roithner Lasertechnik, # 380D30, $6
This LED is a 380nm GaN type in a water-clear 5mm epoxy package. When you first see one, you probably won't be very impressed. But that changes when you take it into a dark room and wait a few minutes for your eyes to adjust. You will then notice it causes fluorescence in a variety of materials, including white cotton, colored package labels, and stray pee around the toilet bowl or cat litter box.


To the unaided eye, this LED appears to have a dim, whitish purple glow, not unlike that produced by the Nichia UV lamp. Most of the radiation is produced in the upper UVA band centered at approximately 380nm, and is not very visible to the human eye; though if it were isolated, it would appear to have a dull, dim purple color to it.


Total power output appears to be not much over 1mW, or just slightly higher than that generated by a Nichia 375nm UV LED. It can illuminate the security strip inside paper money even after the money has been run through a washingmachine and an ordinary "money checker" using a 405nm LED would no longer be able to illuminate it.

I am not familiar with the surface geometry of the die, so I am as of yet uncertain who manufactures this LED or the die used in it. It is not Nichia and it is not Cree. That much I'm sure of. But at $6, you could build a large multi-LED "UV checker" out of these for the cost of a single Nichia.



Roithner Lasertechnik, # HUUV-5102L
I figured it was only a matter of time before Roithner got into the deep violet and near-UV LED game. And they went in headfirst, with an amazing selection of UV and near-UV LEDs now on their sales list. This is their 393-395nm UV model in a water-clear, 5mm epoxy case.

UV LED beam image
The LED color is not the magenta you see in this picture.

The chip geometry is not consistent with any of the violet LED makers who's chips I've actually seen, leaving Toyoda Gosei as the prime suspect. Power output appears to be "moderate", somewhere in the 2-4 milliwatt range. This is consistent with the last known specs on the TG "Super Purple" dice I came across about a year ago. Wavelength of the two tested samples appears to be 394 and 395nm respectively. (When comparing LEDs of this wavelength side by side, you *can* detect a 1nm difference if you know what you're looking for!)

Spectrographic analysis
Spectrographic analysis of this LED.
Ocean Optics USB2000 Spectrometer on loan from TWO-CUBED.




Digi-Key 5mm 380nm UV LED, (www.digikey.com...)
(Rec'd 10-24-02, tested 02-02-04)
I received two of these LEDs from J.M. in Georgia in October 2002, while I was "away". I apologise for taking so long to get these LEDs on my website - the envelope just turned up, so here ya go. :-)

This is a 5mm LED in a water-clear acrylic case, and produces a whitish violet light peaking at 380nm in the UVA band. The radiation is too short in wavelength to get a light meter reading from or run it through the ProMetric, so I don't have that information for you today. This LED produces a substantial broadband emission, but peaks very strongly in the true violet region at the end of the spectrum.

This LED is also available from Lumex, part # SSL-LX5093SUVC. The LED has a rectangular die with two bond wires attaching at each end (rather than at the corners), so this could be a Toyoda Gosei "Super Purple" lamp. I'm not saying it is, but it could be.

Power output is what I'd call "moderate", and appears to be in the 2mW to 4mW range. This is also consistent with Toyoda Gosei "Super Purple" LEDs from mid- to late-2002.


The LED color isn't the magenta you see in this photograph; in reality, the LED produces a dim, whitish violet light. Digital cameras hate longwave UVA (they cannot present the color actually seen), and often distort the color to a purplish or magenta tint.
Beam angle appears to be about 12-15.



Chi Wing 5mm 395nm near-UV LED, (http://stores.ebay.com/chiwingledproductshop)
(Rec'd 12-24-03, tested 12-25-03)
A fan of the website sent me a box of goodies (like batteries, LEDs, flashlights, and a laser); and 9 of these LEDs were among the goodies.
These are Chi Wing's near-ultraviolet (NUV) LEDs, which emit near 395nm in the very deep violet to near-ultraviolet region of the spectrum. It's right there at the end, where the eye doesn't perceive light very well.

The epoxy LED body glows a light blue color; not unlike the LEDTronics NUV and violet LED models do. So there's some kind of UV reactant dopant or dye in there. (I have since heard through a reliable source that recent NUV and violet LEDs from LEDTronics do not glow in this manner.)

The LED has a single-bond construction, so it probably has a Cree Megabright die in there.


The LED color in reality is a dull, deep purple, not the magenta like this photograph makes it appear.
I'm not equipped to measure intensities at wavelengths this short, and I'm not equipped to measure beam angles at all. Looks like about 15 degrees to me.



Sandia creates new UV LEDs
I don't have any of these UV LEDs yet, but here's proof that LEDs can be made at wavelengths as short as 275nm.
(Link opens in a new window)
These LEDs are still more or less experimental, so it might be awhile before they show up here.



ETG, model ETG-5UV395-30, available from ETG
(Added 09-21-02)
This is ETG's high-powered, near-UV LED lamp. It comes in a water-clear 5mm (T1 3/4) epoxy case, and features a powerful Cree MegaBright chip to provide up to 12 milliwatts of near-UV output with a peak wavelength averaging 395nm.

The published specs for this lamp (as furnished by ETG) are:
  Source Material........................ InGaN
  Emitting Color......................... Blue UV (appears more purplish
                                          than the 400-30 or 405-30 lamps)
  Lens Type.............................. Water Clear

Absolute Maximum Ratings (Ta=25C)
  Pulse Current.......................... 100mA
  Avg. Forward Current................... 30mA
  Derating Factor........................ 0.40mA/c
  Reverse Voltage........................ 4.0V
  Operating Temperature.................. -25C to +85C
  Storage Temperature.................... -25C to +100C
  Lead soldering temperature............. +260C for 5 sec.

Electrical & Optical Characteristics (Ta=25C)
  Peak Wavelength (If=20mA)   390nm min, 395nm typ, 400nm max
  Forward Voltage (If=20mA)   3.7V typical to 4.0V max
  Reverse Current (VR=5V)     10uA maximum
  Power Output    (If=20mA)   10mW typical, 12mW max
  Viewing angle               30 typical
ETG violet beam photo
Beam photograph of this LED from ~12".
As with all shortwave sources, the camera does not render the LED color correctly. This LED appears dimmer to the eye than the 400-30 or 405-30 lamps from the same shipment. This is completely normal, and does not indicate a problem with the samples. Human vision loses sensitivity *very* rapidly below around 420nm, so a change of just a few nm can drastically alter the preceived brightness of a light source, even when they measure the same output power. Not that you should stare into one of these things anyway - you really shouldn't do that.

ETG NUV spectroscopic chart

As with other near-UV LEDs on this page, this LED really makes fluorescent materials go apesh!t when you expose them to the beam. Traffic cones turn an angry orange color, and glow-in-the-dark posters come alive quite well at these wavelengths. The security stripe in US currency and the routing marks on US mail also show up well with this LED.



LEDTronics # L200CUV395-12D. (http://www.ledtronics.com), $TBA
This is LEDTronic's offering to the near-UV LED pot. This high powered 395nm LED comes in a typical looking 5mm clear epoxy case with a small amount of some type of UV reactant dye added so the entire LED body glows a bright sky blue color. Some of the shorter wave light at and below 400nm is also scattered, which can be seen as a purplish magenta glow inside the LED in the right-hand picture directly below.

UV LED UV LED
The LED being set up for a test run.

This LED uses the new Cree megabright UV chip. Several other companies are manufacturing LEDs using this chip; so in many instances, only the physical style of the case and leadframe will be different from one company's UV LED to the next. The total light output and the wavelength range should be almost identical in most cases.


UV LED
Power output measurements need to be done, but a preliminary test showed this LED has an optical power output in the 5-8mW range, which is within the specified range for an LED using this chip and driven at no more than 20 milliamps. Some of the light is absorbed & some more of it is scattered by the fluorescent dopant in the epoxy case, but most of it finds its way out.
For this shot, the LED was placed 12" from the target. The camera renders the color incorrectly; the eye would see it as a dull, deep violet glow with no red in it.


UV LED
When you shine the LED at a "day glow" object, such as this Pelican blinker, that object tends to glow brightly. Notice how the green body of the light glows brightly, while the transparent red lens looks basically black.



Wilycon # WUV503-C395-C, Wilycon Corp. (http://www.led-center.com), $0.65 each for more than 50,000 pcs
This is a 395nm near-UV LED, which makes the unknown sample that came in the flashlight (moved to the Violet LED page) a 405nm model. With wavelengths this short, you pretty much have to line them up side by side to tell the difference until you get used to seeing things at this end of the spectrum. In this regard, even I'm a bit new at this. :-O

This LED uses the Cree Megabright series UV dice, and should be outputting 10-12mW of radiant power when run at 20mA.

For the more technically-minded, here are the basic specs for this part:
        Absolute Maximum Ratings
        Continuous DC Forward Current (If): 30mA maximum
        Pulse Forward Current (Ifp): 100mA maximum
        Reverse Voltage (Vr): 5 volts

        Typical operating conditions:
        DC Forward Voltage (Vf) at 20mA: 3.7 volts typical, 4.0 volts max
        DC Reverse Current (Ir): 10 microamps maximum
        Radiant Flux (P): 10mW minimum, 12mW typical
        Wavelength: 390nm minimum, 395nm typical, 400nm max
        Spectral line half width: 20nm typical
        Rise time: 30 nanoseconds typical



Just want to see one going in a computer case? Too bad it's only for the picture.
I'll have to wait till I get a bunch of these as I can't use the only test unit for frivolous purposes. :)


When viewed side by side, the 395nm version has a more "purple" look to it than the 405nm version. It also causes a brighter fluorescent glow in things like dead TV tubes and copying machine paper than the 405nm one.

Wondering if someone pissed the bed in your hotel room and the maid didn't change the sheets before you got there? A near-UV source like this *might* help you find it on the sheets or on the mattress. But you might have a bit more luck using the Nichia UV, because old urine glows a bit brighter at shorter wavelengths. Same with cat pee in the rug.

* This price applies only when you tell Ken Ma that you saw this page.
They cost $2.95 apiece in small quantities.
Wilycon is also selling UV/Violet LED Keychain Flashlights with this LED in it for $8 each plus $5 shipping. The light is very small, and runs on a pair of CR2016 lithium coin cells (included). It comes in a transparent body with a keyring attachment. You can e-mail Ken about those too.



Nichia America, NSHU550E, www.nichia.com, estimated $33.00 apiece
For decades, scientists have been searching in vain for a way to make deep blue and violet LEDs; this changed about a year ago with Nichia's new ultraviolet breakthrough.

Packaged in a metal can-style TO-18(?) case with a glass window, this LED looks more like an old-style phototransistor than it does an LED. When it is powered up with 5 or 6mA, the UV emission becomes very apparent - much more so when run near its 15mA maximum rating.

To the eye, it gives off a dim purplish white glow, similar in some ways to argon gas glowing around the electrodes in a fluorescent starter - but it shows a good, extremely strong emission at around 370nm in the invisible, ultraviolet portion of the spectrum.


This emission is quite invisible to humans; all you'll see with the unaided (but protected) eye is the weak purplish-white glow of the LED's visible emission.
This visible emission appears to be broadband, giving a continuous spectrum from red to blue-green; a dip or gap appears in this region, then the LED shows some spikes (increased emission) again in the deep blue and violet - extending past visibility and well into UV, where this LED emits most of its energy in a single, narrow band.

This LED is more delicate than most, and I have read the spec sheets stating that Nichia rates it for a continuous maximum current of 15mA; it is also equipped with a protective zener diode built-in.
The first sample I obtained was damaged both physically (the case was drilled through, as you see below) and also has damage to the chip at the subatomic level. A second, intact sample operates normally, as the manufacturer intended it to.
Some types of bleached paper fluoresce a very bright electric blue when this LED is aimed at it; other inks and dyes will also fluoresce similarly (see photo)
Virtually anything which fluoresces under longwave UV should glow brightly under this LED.

paper fluorescing under UV
Paper fluorescing brightly near the UV LED's emitting area.


This is one LED that you should NEVER, EVER look at directly with your eyes. This is because the invisible ultraviolet radiation is harmful to them, and can cause corneal fogging that mimics cataracts; and can cause even more severe damage to your eye's lens with only slightly prolonged exposure.

caution UV radiation

Thankfully here, the LED's UV emission is all long-wave, and not the even nastier medium and shortwave kind. If you need to view this LED directly for any reason (studying it, curious, etc.), obtain a UV filter and place it between your eyes and the LED's window before you try feeding this LED any power.

Don't let the sickly, weak whitish glow fool you. This comprises only a few percent of the LED's actual energy output - the rest, a whopping 1 milliwatt of radiant output, is in that nasty UV range.



From left to right:
L: The first sample LED photographed in bright room light, notice the paper fluorescing even when brightly illuminated already.
C: Closeup of the poor injured thing, showing holes that had been drilled into its can-shaped outer case.
R: A piece of garbage mail fluoresces a bright blue under the LED's invisible radiation.

Notice in the first two photos, this particular sample is missing its glass window and it has several holes drilled through its casing; its previous owner must have removed its window so he could more closely study the internal structure or to increase the radiation flux density. The LED functions, but without its protective window, it must remain wrapped in foil and bagged when not in use so as to avoid damage or contamination of the emitting chip at the bottom. The intact sample I have does just fine stuck into a piece of anti-static foam.



1: Specifications
(Absolute Maximum Ratings) (Ta = 25 C)

        Item               Symbol       Absolute Maximum Rating      Unit
Forward Current              If                   15                    mA
Pulse Forward Current        Ifp                  30                    mA
Allowable Reverse Current    Ir                   85                    mA
Power Dissipation            Pd                   60                    mW
Operating Temperature        Topr              -30 ~ +80                deg. C
Storage Temperature          Tstg              -40 ~ +100               deg. C
Lead Soldering Temperature   Tsol  260 deg. C for 5 sec (3mm from base) deg. C

Pulse current test conditions: Pulse width <=10msec. Duty cycle <=10%
------------------------------------------------------------------------------

(Initial Electrical/Optical Characteristics) (Ta = 25 C)

        Item             Symbol   Condition       Min   Typ   Max  Unit

Forward Voltage            Vf     If=10mA         ---   3.9   ---    V
Optical Power (NSHU550E)   Po     If=10mA         ---  1000   ---   uW
              (NSHU590E)   Po      f=10mA         ---   750   ---   uW
Peak Wavelength            xP     If=10mA         ---   370   ---   nm
Spectral Line Half Width   xx     If=10mA         ---    12   ---   nm

Note: Power measurement error can be up to 10% in either direction.






Left:: Close-up of the LED, showing the chip inside.
Right: Another view of the LED's business end.


new UV
This photograph shows what the UV LED does to a household camera.

Notice how badly it overloaded and created all kinds of refractions due to the excessively bright UV emission, which the camera interprets as a magenta hue.

This is the intact specimen that ended up as a museum piece in the Decade 2000 exhibit.






[[BEGIN SERMON MODE]]
Again I must emphasize, protect your eyeballs when using one of these LEDs. You only get one set of eyes - and if you wreck them, you can't just go down to the local seven-eleven and buy a can of them.
Here is one simple way you can do this:

Most sunglasses and some prescription eyeglasses have some degree of UV protection already; to determine if yours do or not, aim the LED at something that clearly fluoresces (such as those neon green & orange stickers that occasionally show up on your mail, day-glow orange price tags, or painted portions of a blacklight poster), positioning the LED so the object in front of it glows (fluoresces) brightly from the ultraviolet light. Then put the glasses between the face of the LED and the target. If the glow stops or dims dramatically, the glasses are stopping the UV and you can use them as eye protection at least for short-term use.
However, if the glow remains or dims only slightly, look for another pair.

In any case, never look directly at the LED without eye protection - not even for a minute.

Symptoms of UV exposure may not appear immediately; they can be delayed by 30 minutes to several hours. They can include a burning or "sand in the eyes" sensation, and a hazy look around light bulbs and other bright objects. Mild cases are self-correcting within 24 to 36 hours; however if despite my warnings you still stared at the LED from close range for more than a few minutes, it might not be a bad idea to see an eye doctor and tell him you've been exposed to UVA radiation.

DISCLAIMER: I shall not be held responsible for any damage or loss of eyesight arising from your use or misuse of the information on this page. Thank you for listening.
[[END SERMON MODE]]









WHITE 5500-6500K InGaN+phosphor 
ULTRAVIOLET 370-390nm GaN 
BLUE 430nm GaN+SiC
BLUE 450 and 473nm InGaN
BLUE Silicon Carbide
TURQUOISE 495-505nm InGaN
GREEN 525nm InGaN 
YELLOW-GREEN 555-575mn GaAsP & related
YELLOW 585-595nm
AMBER 595-605nm
ORANGE 605-620nm
ORANGISH-RED 620-635nm
RED 640-700nm
INFRARED 700-1300nm
True RGB Full Color LED
Spider (Pirrahna) LEDs
SMD LEDs
True violet (400-418nm) LEDs
Agilent Barracuda & Prometheus LEDs
Oddball & Miscellaneous LEDs
Programmable RGB LED modules / fixtures
Where to buy these LEDs 
Links to other LED-related websites
The World's First Virtual LED Museum
The Punishment Zone - Where Flashlights Go to Die
Legal horse puckey, etc.
RETURN TO OPENING/MAIN PAGE
LEDSaurus (on-site LED Mini Mart)



This page is a frame from a website.
If you arrived on this page through an outside link,you can get the "full meal deal" by clicking here.